Grinder



M. c. HUTT GRINDER Filed July 20, 1925 Patented Oct. 30,

UlSuTED STA MARSDEN c. Hurt-ro, or DE'rRp-oi'r, MICHIGAN.

GRINDER.

Application led July 20, 1925. 'Sierial No. 44,644. j

This invention relates to grinders and the obj ectof the invention is to provide a. grinder e for grinding small cylindrical apertures.

Another object of the invention is to provide a'grinder in which the operative grinding dia-meter of the grinding stonesmaybe adjusted to grind exactly to a desired siZe.

Another object of the invention is to provide a holder of die cast metal in which the grinding stones 'are embedded,l a series of three holders being provided in each grinder adapted to be5 moved outwardly or inwardly in relation to the grinder body for grinding different diameters.- n

Another object of the invention is to provide a grinder in which the grindingudia-me-l ter may be adjusted during the grinding operation. l

These objects and the 'several novel fea-1 tures of the invention are hereinafter morey fully described and claimed and the pre ferred form of construction by whichthese objects are attained is shown in the accom-y panying drawings in which- Fig. lis a longitudinal section through a grinder embodying my invention. l

Fig..2 is an elevation thereo-f. f

Fig. 3 isa section taken online 8*-3 of Fig. 1.

Fig. 4 is a section through- Va smaller grinder of this type.

v. Fig. 5 is a perspective view of the stone and holder for the smaller grinder.

Asr shown in.Figs.'1, 2 and 3 the grinder consists of a tubular body 1 having a. keyway 2 therein in'which the key 3 is positioned. A cone `4 ispositioned within the tubular body 1 and is provided with a. keywayfitting the key 3. The body 1,-isV providedwith a series of three slots opening therethrough and a stoneholder 5 is moginted inleach slot. A cone 6 is vmounted in the end of thetubulan body 1 opposite the cone 4 and the stone the stone holders 5 at each-end are provided with angular faces fitting the cones 4 and 6. uThe. body member 1 isp-rovided with an annular groove at each end of the stone holders 5 and holders 5 are each p'rovided with grooves registering with the grooves.k in the body member'l. lA pair of spring rings 7 are spring rings 7 Lthe `stone holders ar fheld in' engagement with the l e 6 is rotatably mounted on a shaft 8 whichis threaded into the cone 4 and the end ofthe,

. grinding I e this operation maybe repeated until the apercones 4 and6. VThe' cone` sha-ft 8 "extending through the cone KA6 is secured in an adjusting knob 9 by the pin 10. The knob 9 is provided with a knurled face 11 and by turning the knob 9 in one direction in rela-tion to the body l; the shaft 8 secured thereto is threaded into the cone 4 thus drawing the cones and 4 together.` In .this operation both cones are moved equally and move the th'ree holders 5 outwardly against the tension ofthe spring rings 7.

In the form shown in Fig. 41 each holder 5 is provided with ltwo stones 12. The holders 5 are formed of die cast metal andare cast `with the angular faces fitting the cone-s 4 and 6 and with the grooves for the spring rings .7. The stones 12 are die cast'in the holders 5, and the stone-s, 12 are held in the mold While the holder is being die cast so that the stones 12 are in perfect alignment and are each parallel .with the longitudinal axis of the respective holder. In this way the stones 12 are always true inr the holders and this type in whiclrtwo stones areut-ilized is adapted for grinding two apertures to the same `size at the same. time such as the two wrist pin holes in a piston. The grinder is driven by means of the shaft 18 which is connected to thebody 1 by a universal con- 4neetor 14. The grinder is inserted in the wrist pin'apertures of a pistonwith the stones 12 engaging the-.Walls of the apertures. As the grinder body is rotated the grinding stones -grind the.. inside walls of the apertures until the stones begin to free themselves at the knob which ytime the operator may grasp -11 for an instant While the tool is rota ing which vturns the shaft 8 in relation tot e grinder body 1 to `move the cones 4 and 6 together slightly.

This increases the tures are ground to size.

4knob 11 may berotated to unserewthe shaft diameter of the stones slightly andV` 8 in the cone 4 and the-spring rings 7 conj tract the stone holders 5 and force the cones apart aslthe shaft 8 is unthreaded in the cone 4 and by this arrangement the cones 6 and 41are inoved apart equally until the desi-red -smaller.`dia`meter'i s reached. i

notched t0 t'i'he keyi 18 Which .fits yin a i i `Ajaslightly different form of tool is shown igs. `4` and 5 in 'which atubular body7 mem-v @rib-is provided having a shank 1.6 adapted to be secured in a chuck byxwhicli the ftol'isr rotated`-` -With this` form the cone 17 is 'cast withl the grinding stones 24 embeddedy therein and are p-rovided with angular faces 25 fitting the cones 17 and 20. There are -three holders 23 provided which extend through the body member in the same manner' as the holders shown in Fig. '3. The body member is provided with two annular grooves for the spring rings 26` and the holders are provided with grooves 27 for the said spring rings. This ydevice is utilized for grinding apertures of smalldiameter and is adjustedv in the same manner as the formshown in Figs. 1, 2 and 3.` By turning the knob 21 the 'shaft 19l is threadedinto they cone 17 to move the cones 17 and 20 together and move the holders' and stones outwardly radially from the een# ter of the tool and by reversingj the rotation of the knob`21 the cones 17 and 2() are moved apart and the holders 23 are retracted yradially by the spring rings 26 which hold the holders 23 in engagement with the cones.

From the foregoing description it becomes evident that the device is very "simple and eii-v and desire lto secure by Letters Patent of. the

1. In a grinder for truing cylindrical apertures, a hollow body member, a series of abrasive holders mounted in the body member and adapted for movement radially therein, a pair of cones in the body member, a-shaft extending between the cones and adapted by rotation to vary the distance apart of the cones, said holders 'being formed with integral tapered portions'at opposite ends to t the respective acones and spaced abrasive members carried at opposite ends of the holders, the cones and connecting shaft being movable as a unit on longitudinal axis of the body and limited in such movement by reason of engagement with the respective tapered portions of the stone holders, the cones positively fixing the general "limit of contraction of the abrasivedevices in .l

tures, a hollow body member having a series of longitudinally extending radial kslots therein, a series of abrasive holdersifitting the said V slots, means in the body for adjusting the holders radially in the slots, and an abrasive member adjacent each end of each holder providing a. tool'witha series of abrasive elements y.

in longitudinally spaced relation adapting the same for grinding'pairs of spaced apertures in axial alignment.

tion.

MARSDEN C. HUTTO.

In testimony whereof I sign this speciiica-' 

